JPH09311609A - Electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress electrostatic fatigue as well as physical wear of a photosensitive member, and furthermore, physical wear of a drive system, and to reduce the running cost, by starting operation of an image forming unit with the same timing as in the case of paper feeding to the main body when a hard copy is outputted by optional paper feeding. SOLUTION: This device, having optional paper feed units 221, 222 in addition to a main body paper feed unit 211, is equipped with a recording paper detection means 20, located upstream of a transfer part 5, in such a position as to be able to detect a front end position of recording paper, whichever case happens where paper is fed by the main body paper feed unit 211 or by the optional paper feed units 221, 222, and at a point of time when a front end of recording paper is detected by this recording paper detection means 20, the recording paper is once stopped and thereafter conveyance toward the transfer part 5 is resumed. In this event, image forming operation is started based on the detection of the recording paper detection means 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, and more particularly to an electrophotographic apparatus such as a copying machine, a plain paper facsimile and a printer.

[0002]

2. Description of the Related Art FIG. 8 is a schematic configuration diagram of an essential part for explaining an outline of an electrophotographic process. In the illustrated example, it is assumed that a photoconductor 1 rotates counterclockwise (in the direction of an arrow). As is well known, the surface of the photoconductor 1 is uniformly charged by the charging unit 2, and
Is exposed by the optical writing unit 3 that moves in accordance with the rotation, and a latent image is formed. Further rotation, a toner image is selectively attached and developed according to the latent image in the developing unit 4, and a toner image is formed. This toner image contacts the cut paper 10 fed from the paper feed roller 11 and the registration roller 12 in synchronization at a certain timing at the transfer unit 5, and is transferred onto the cut paper 10. The cut sheet 10 to which the toner is attached after being transferred is fixed by the fixing unit 6, discharged from the paper discharge unit 7 to the outside of the machine, and made into a hard copy. on the other hand,
After passing through the transfer unit 5, the photosensitive member 1 collects the toner or the like that could not be transferred completely at the cleaning unit 8, makes the surface potential of the photosensitive member approximately 0 V at the charge eliminating unit 9, and returns to the charging unit 2 again.
These series of operations are repeated to continuously form hard copies. The photoconductor 1 is rotationally driven by a photoconductor drive motor (not shown).

[0003]

FIG. 9 is a flowchart showing an example of control of a conventional electrophotographic apparatus.
In the conventional electrophotographic apparatus, the rotation of the photoconductor drive motor (not shown) is started when the page memory is always full regardless of the type of recording paper unit selected (main body feeding, optional paper feeding). (S1 to S3). However, in the case of option paper feeding, the distance from the paper feed start position to the transfer nip position is longer than in the case of main body paper feeding, and if roll paper is used, a cutting operation for recording paper is additionally required. As compared with the main body feeding, it takes a longer time from the start of the feeding operation until the recording paper reaches the transfer nip position. Therefore, in case of optional paper feeding,
The photoconductor was rotated more than necessary compared to the main body feeding. For this reason, for example, electrostatic fatigue or physical wear of the photoconductor is larger than that in the main body feeding, which may cause a problem in the life of the photoconductor or the drive system.

According to the first aspect of the present invention, when a hard copy is output by optional sheet feeding, the operation of the image forming unit is started at the same timing as the sheet feeding of the main body, and electrostatic exposure and physical abrasion of the photoconductor, and further Aims to suppress the physical wear of the drive system and reduce the running cost.

A second object of the present invention is to correct a timing difference between the image forming side and the sheet feeding side in the transfer section.

A third object of the present invention is to further match the timings of the image forming side and the paper feeding side in the transfer section.

According to a fourth aspect of the present invention, when a hard copy is output by optional sheet feeding, the operation of the image forming unit is started at the same timing as the sheet feeding of the main body, and electrostatic exposure and physical abrasion of the photoconductor, and further Aims to suppress the physical wear of the drive system and reduce the running cost.

It is another object of the present invention to make the timings of the image forming side and the sheet feeding side in the transfer section coincide with each other.

According to a sixth aspect of the invention, the rotational speed of the photosensitive member is set to the same minimum rotational speed as in the case of feeding the main body, and electrostatic exposure and physical wear of the photosensitive member, and further, physical driving system The purpose is to suppress excessive wear and reduce running costs.

[0010]

In order to achieve the above object, the invention of claim 1 has an optional paper feeding unit in addition to the main body paper feeding unit, and is located upstream of the transfer section and in the main body paper feeding unit. The recording paper detecting means is provided at a position where the leading edge position of the recording paper can be detected regardless of whether the leading edge position of the recording paper is detected by the recording sheet detecting means or the optional sheet feeding unit. In the electrophotographic apparatus which resumes the conveyance toward the transfer portion after stopping the paper, the image forming operation is started based on the detection by the recording paper detection means.

According to a second aspect of the present invention, the time required for the leading edge of the recording paper to reach the transfer portion is shorter than the time required for the leading edge of the image formed on the image carrier to reach the transfer portion. After the image forming operation is started, the conveyance of the recording paper is restarted with a delay of a predetermined time.

According to the third aspect of the present invention, the predetermined time is the time until the leading edge of the image formed on the image carrier reaches the transfer portion and the time until the leading edge of the recording paper reaches the transfer portion. It is characterized in that it corresponds to the time difference.

According to a fourth aspect of the present invention, there is an optional paper feeding unit in addition to the main body paper feeding unit, and means for selecting the paper feeding unit according to the size of the recording paper, and each selected paper feeding unit. It is characterized in that it has means for delaying the start of the image forming operation for a certain period of time.

According to a fifth aspect of the present invention, the time until the recording paper fed from the main body paper feeding unit reaches the transfer portion and the recording paper fed from the selected paper feeding unit It is characterized in that it corresponds to the time difference of the time required to reach the transfer portion.

According to a sixth aspect of the present invention, an optional paper feeding unit is provided in addition to the main body paper feeding unit, and the paper is fed upstream of the transfer unit from either the main body paper feeding unit or the optional paper feeding unit. However, the recording paper detection unit is provided at a position where the leading end position of the recording paper can be detected, and once the recording paper detection unit detects the leading end position of the recording paper, the recording paper is temporarily stopped and then conveyed toward the transfer unit. In the restarting electrophotographic apparatus, if the optional paper feeding unit is selected, the recording paper is moved to a position where it can be synchronized with the image on the image carrier at the same timing as the paper feeding timing of the main body feeding before the paper feeding operation is started. It is characterized by having a means for pre-feeding.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration for explaining an embodiment according to the present invention. In the figure, reference numeral 211 denotes a main body sheet feeding section, 22
1 is an option 1 paper feeding unit, 222 is an option 2 paper feeding unit, 231 is a simple paper feeding unit, A is a main body fed recording paper leading end position, B1 is an Option 1 fed recording paper leading end position, B2 is an Option 2 feeding paper Recording paper leading end position, C is simple paper feeding recording paper leading end position, D is registration roller nip position, E1 is option 1 paper feeding roller nip position, E2 is option 2 paper feeding roller nip position, and F is simple The nip position of the paper feed roller, G is a sensor ON position at which a registration sensor (recording paper detection means) 20 for detecting the leading end of the recording paper is turned on, and H
1 is an option 1 paper feed sensor ON position in which the option 1 paper feed sensor that detects the leading edge of the recording paper fed from the option 1 paper feed portion 221 is turned on, and H2 is a record fed from the option 2 paper feed portion 222 Option 2 which detects the leading edge of paper The paper feed sensor turns on Option 2 paper feed sensor O
An N position, I is a manual feed sensor ON position in which a manual feed sensor that detects the leading edge of the recording paper manually fed from the simple paper feed unit 231 is turned on, and K is a toner image on the photoconductor 1 that is recorded on the recording paper 10.
In the transfer nip position where the image is transferred to, the same reference numerals as in the case of FIG. 8 are attached when other operations similar to those of the electrophotographic apparatus shown in FIG. 8 are performed.

Next, the inventions of claims 1 to 3 will be described in detail. In the following description, the unit of time is seconds,
The unit of length is mm and the unit of speed is mm / sec. Now, the minimum rotation time of the photoconductor 1 required for the recording paper (cut paper) to reach the transfer nip position K after the photoconductor 1 (image carrier) starts rotating on the image forming system is: t1: photoconductor drive motor start-up time (from the start of rotation of the photoconductor drive motor until it locks to a certain number of revolutions) t2: after the photoconductor drive motor locks, optical writing is performed on the photoconductor 1. Assuming that the time required for the toner image to reach the transfer position after development (time for the photoconductor 1 to rotate from the optical writing position to the transfer nip position K) is (t1 + t2), this (t1 + t2)
Is the photoconductor 1 after the photoconductor drive motor starts rotating.
This is the time required for the leading edge of the image that has become a toner image to reach the transfer nip position K through the above processes of charging, exposure, and development.

On the other hand, the installation position of the registration sensor 20 (sensor ON position G) is L1: distance from the recording paper detecting means 20 to the transfer nip position K, V1: recording paper transport speed, L1 ≦ (t1 + t2) × The position that satisfies V1 is set.

The recording paper 10 is fed from a paper feed unit selected from the main body paper feed unit 211 or the optional paper feed units 221 and 222, and the leading edge of the recording paper is the registration sensor 2.
After being detected as 0, the operation is temporarily stopped. Then, L1 = (t
In the case of 1 + t2) × V1, the recording paper 1
At the same time when 0 is sent to the transfer nip position K, the driving of the photoconductor drive motor is started, and L1 <(t1 + t2) × V1
In the case of, after the recording paper 10 is temporarily stopped, t3 = (t1 + t2) −L1 / V1 from the start of driving the photoconductor drive motor.
Then, the recording paper 10 is started to be sent to the transfer nip position K after being delayed by just that amount.

That is, L1 <(t1 + t2) × V1 means L1 / V1 <(t1 + t2), and L1 / V
Since 1 indicates the time from when the recording paper 10 which has been stopped is resumed to when the leading edge of the recording paper 10 reaches the transfer nip position K, an image which has become a toner image after the photoconductor drive motor starts rotating. It takes longer than the time for the leading edge of the recording paper 10 to reach the transfer nip position K.
It takes less time to reach. The delay time t3 is to fill the time difference and adjust the timing.

By performing this operation, the recording paper 10
And the tip of the toner image on the photoconductor 1 simultaneously enter the transfer nip position K, and the movement (rotation) of the photoconductor 1 and the recording paper 1
It is possible to synchronize the movement of 0, regardless of the type of recording paper unit selected (main body feed, optional paper feed)
The time from the start of rotation of the photoconductor drive motor until the leading edge of the recording paper reaches the transfer nip position K is constant (t1 + t
2), and it is the minimum time.

In addition, the minimum rotation time of the photoconductor 1 from when the charging unit 2 is turned on to when the recording paper (cut paper) reaches the transfer nip position K on the image forming system is t4: photoconductor This is the time until the developed toner image reaches the transfer nip position K after the optical writing is performed on the charged portion on the position 1 (time for the photoconductor 1 to rotate from the charging position to the transfer nip position K). Is the time from the start of charging on the photoconductor 1 to the transfer nip position K at the leading edge of the image that has become a toner image after the processes of charging, exposure and development. On the other hand, the installation position of the registration sensor 20 (sensor ON
Position G) is a position that satisfies L1 ≦ t4 × V1.

The recording paper 10 is fed from a paper feed unit selected from the main body paper feed unit 211 or the optional paper feed units 221 and 222, and the leading edge of the recording paper is the registration sensor 2.
After being detected as 0, the operation is temporarily stopped. And L1 = t4
In the case of × V1, the charging unit 2 is turned on at the same time when the recording paper 10 is started to be transferred to the transfer nip position K, and in the case of L1 <t4 × V1, the charging unit 2 is turned on and then t5 = t4−L1 / V.
After delaying by 1, the recording paper 10 starts to be sent to the transfer nip position K. That is, L1 <t4 × V1 means L1
/ V1 <t4, and L1 / V1 indicates the time from when the transportation of the recording sheet 10 which has been stopped is resumed until the leading edge of the recording sheet 10 reaches the transfer nip position K. Therefore, charging on the photoconductor 1 is started. The time from when the leading edge of the image, which has become a toner image, to the transfer nip position K, is longer than the recording sheet 10
The time required for the leading edge of the sheet to reach the transfer nip position K becomes shorter. It is the delay time t5 that fills this time difference and adjusts the timing.

By performing this operation, the recording paper 10
And the tip of the toner image on the photoconductor 1 simultaneously enter the transfer nip position K, and the charging unit 2 is turned on regardless of the type of recording paper unit selected (main body feeding, optional paper feeding). The time from when the leading edge of the recording paper reaches the transfer nip position K is constant (t4), and is the minimum time.

Next, the inventions of claims 4 and 5 will be described in detail. FIG. 2 is a flow chart showing an embodiment of the present invention. When the electrophotographic apparatus is a facsimile apparatus, it starts receiving image information, and in the case of a copying machine, when the copy start button is pressed, respectively. Start recording preparation. First, one page of image information is stored in the page memory, and when the page memory is full (S1), an appropriate recording paper size is determined according to the amount of image information in the page memory, and based on the determined recording paper size. A paper feed unit (main body paper feed, option 1 paper feed, option 2 paper feed) is selected (S2). Further, the delay time T1 is set according to the selected paper feeding unit (S3).
The setting of 1 will be described in detail.

For example, the time from the start of paper feeding of each paper feeding unit to the arrival of the leading edge of the recording paper at the transfer nip position K is: Main body paper feeding: Ta = 1 second Option paper feeding first stage: Tb = 2 seconds Optional paper feed second stage: Tc = 3 seconds Roll paper feed second stage: Td = 6 seconds If all the paper feeding units are set, the rotation time of the photoconductor 1 until the start of recording is supplied by the main body. In order to make it the same as that for paper, the delay time T1 may be set to T1 = Tn−Ta (n = a, b, c, d) (for example, if the optional sheet feed is the second stage, T1 = Tn−Ta).
1 = Tc-Ta = 2 seconds). Also, T1 = (t1 + t2)
Then, the minimum rotation time is required from the start of the rotation of the photoconductor 1 to the arrival of the recording paper 10 at the transfer nip position K.

Returning to FIG. 2 again, the sheet feeding operation (rotation of the optional sheet feeding motor) in the sheet feeding unit selected in S2 is started (S4), and thereafter, the flow is the movement of the optional sheet feeding unit side and the electrophotography. The movement of the main body of the device progresses in parallel. First, the optional paper feed motor is temporarily stopped, the recording paper that has started to be fed in S4 is stopped at, for example, the registration roller position, and at the same time, the T timer is set (S).
5). After that, it is determined whether the electrophotographic apparatus main body is in the standby state and the T timer has timed out (S
6) If YES, the subsequent recording operation is started, while N
If O, the monitoring routine is repeated until YES.

On the other hand, in the main body of the electrophotographic apparatus, a timer having a delay time T1 is set at the same time when the paper feeding operation of S4 is started, and
After one lapse of time (S7), the intermediate roller bias and the developing roller bias are set (S8). Next, the rotation of the photoconductor drive motor is started (S9), and it is monitored whether the motor is in a locked state (whether the rotation speed is constant) (S10). Continue this monitoring until it locks
When ES is reached, the charging is switched from the off state to the on state, and at the same time, LD sampling for synchronous detection of optical writing and power adjustment is performed, and further, the developing bias switching time (the first charged position on the photoconductor is the developing position). A timer for measuring the time to move to the position is set (S11).
Then, after the developing bias switching time has elapsed (S12
If YES, an instruction to change the bias between the intermediate roller and the developing roller is issued (S13), and the apparatus enters the standby state (S14).
When this standby state is recognized in the previous S6, thereafter, a normal electrophotographic recording operation such as optical writing of image information is performed.

FIG. 3 is a flow chart showing another embodiment of the present invention. The electrophotographic apparatus starts recording preparation at the time of starting reception, determines a recording paper size from protocol information communicated after the start of reception, and selects a paper feed unit based on the determined recording paper size (S1). Then, the delay time T1 is set in the same manner as S3 in FIG.
2) After that, the recording operation is performed in the same manner as in FIG. When the electrophotographic apparatus is a printer, the paper feeding unit is selected based on the recording paper size determined at the start of one job, and thereafter, the delay time T1 is set in the same manner and the same as in FIG. The recording operation should be performed.

4 and 5 are flow charts showing a further embodiment of the present invention. When the electrophotographic apparatus is a facsimile apparatus, it starts receiving image information, and in the case of a copying machine, it starts copying. When you press the button, each will start recording preparation. First, one page of image information is stored in the page memory, and when the page memory is full (S1), the intermediate roller bias and the developing roller bias are set respectively (S2). Next, the rotation of the photoconductor drive motor is started (S3), and it is monitored whether the motor is in a locked state (whether the rotation speed is constant) (S4). Continue this monitoring until the lock state is reached, and if YES, determine the appropriate recording paper size based on the amount of image information in the page memory, and based on the determined recording paper size, the paper feeding unit (main body feeding, optional 1 paper feed, option 2 paper feed is selected (S5). Further, the delay time T2 is set according to the selected paper feeding unit (S6).
The setting of 2 will be described in detail.

For example, the time from the start of feeding of each paper feeding unit to the arrival of the leading end of the fed recording paper at the transfer nip position K is: Main body feeding: Ta = 1 second Optional feeding first stage: Tb = 2 seconds Optional paper feed second stage: Tc = 3 seconds Roll paper feed second stage: Td = 6 seconds When all the paper feeding units, useless charging time that does not directly contribute to image formation is eliminated. In order to set the delay time T2 to T2 = tn-t4 (n = a, b, c, d), the recording paper 10 is transferred to the transfer nip position after the photoconductor 1 starts to be charged on the image forming system. The charging time is the minimum required to reach K.

4 and 5 again, the sheet feeding operation (rotation of the optional sheet feeding motor) in the sheet feeding unit selected in S5 is started (S7), and thereafter, the flow is the same as the movement of the optional sheet feeding unit side. The movements of the electrophotographic apparatus body side proceed in parallel. First, the optional paper feed motor is stopped to temporarily stop the recording paper that has started to be fed in S7, and at the same time, the T timer is set (S8). After that, it is judged whether the main body of the electrophotographic apparatus is in the standby state and the T timer has timed out (S9), and when the conditions are satisfied (S9 YES), the drive of the optional paper feed motor is restarted (S10), and the operation is restarted. When the leading edge of the recording paper which has started to be conveyed reaches the sensor ON position G and the registration sensor 20 is turned on (YES in S11), the optional paper feeding motor is stopped again (S12). In this state, the start of conveyance of the recording paper by the paper feed motor on the main body side is monitored (S13), and when the main body paper feed motor is driven (S13 YES), the drive of the optional paper feed motor is started again (S14).

On the other hand, the main body of the electrophotographic apparatus sets a timer of delay time T2 at the time of starting the paper feeding operation of S7, and sets T2.
After the lapse of time (S15), the charging is switched from the off state to the on state, and at the same time, LD sampling for synchronous detection of optical writing and power adjustment is performed, and further, the developing bias switching time (the first charged position on the photoconductor is Set a timer to measure the time to move to the developing position (S1)
6). After the developing bias switching time has elapsed (S
17 YES), gives an instruction to change the bias of the intermediate roller and the developing roller (S18), and enters the standby state (S1).
9). In this state, when the drive of the optional paper feed motor in S10 is detected (YES in S20), the drive of the paper feed motor on the main body side is started (S21), and the leading edge of the conveyed recording paper reaches the sensor ON position G and the registration sensor When 20 is turned on (S22 YES), the main body side sheet feeding motor is stopped (S23). After that, a normal electrophotographic recording operation such as optical writing of image information is performed.

6 and 7 are flow charts showing another embodiment of the present invention. First, one page of image information is stored in the page memory, and when the page memory becomes full (S
1), the intermediate roller bias and the developing roller bias are set respectively (S2). Next, the rotation of the photoconductor drive motor is started (S3), and it is monitored whether the motor is in a locked state (whether the rotation speed is constant) (S4). Continue this monitoring until it becomes locked, and if YES,
The recording paper size is determined from the protocol information communicated after the start of reception, and the paper feed unit (main body paper feed, option 1 paper feed, option 2 paper feed) is selected based on the decided recording paper size (S5). Subsequently, the delay time T2 is set in the same manner as in S6 of FIG. 4 (S6), and thereafter, the recording operation is performed in the same manner as in FIG. When the electrophotographic apparatus is a printer, the paper feeding unit is selected based on the recording paper size determined at the start of one job, and thereafter the delay time T2 is set in the same manner as in FIGS. The recording operation may be performed in the same manner.

Finally, the invention of claim 6 will be described in detail. If the electrophotographic apparatus has only one optional sheet feeding, the optional sheet feeding is pre-fed before the sheet feeding operation. The timing of pre-feed is from the time the power is turned on to the start of recording, and from the end of the optional paper feed to the start of the next paper feed operation.
The leading edge position of the recording paper after pre-feeding is a position that satisfies the following conditions before joining the main body paper feed. t6: The sensor is turned on at the leading edge of the recording paper from the start of feeding the main body
Time until the registration sensor 20 is turned on after the position G is reached (t6 = Ta) t7: The recording paper is fed again after pre-feeding, and the leading edge of the recording paper reaches the sensor ON position G and the registration sensor 20 is turned on. It is a position that satisfies t6 = t7, where

The pre-feed recording paper may be stopped at a predetermined position by controlling the time from the start of the optional paper feeding operation by a timer, or a sensor (recording paper detecting means) may be provided at a predetermined position to output the sensor output. It may be stopped on the basis. When recording is started in the pre-feed state, t6 = t7
Therefore, the recording time is the same regardless of whether the paper is fed from the main body paper feed unit or the optional paper feed unit. Also, t6 = t1
When + t2 is set, the minimum rotation time is required from the start of the rotation of the photoconductor 1 on the image forming system until the recording paper 10 reaches the transfer nip position K.

[0037]

In the electrophotographic apparatus according to the first aspect of the present invention, the leading edge position of the recording paper is detected regardless of whether the paper is fed from the main body paper feed unit or the option paper feed unit, upstream of the transfer section. Equipped with recording paper detection means at a position where
By starting the image forming operation based on the detection of the recording paper detection means, when the hard copy output by the optional paper feeding, the operation of the image forming unit is started at the same timing as the main body feeding, and the electrostatic charge of the photoconductor is started. The running cost can be reduced by suppressing the physical wear and wear of the drive system and the physical wear of the drive system.

In the electrophotographic apparatus according to the second aspect, the time taken for the leading edge of the recording paper to reach the transfer portion is longer than the time required for the leading edge of the image formed on the image carrier to reach the transfer portion. If the length is short, after the start of the image forming operation, the conveyance of the recording paper is restarted with a delay of a predetermined time, whereby the timing deviation between the image forming side and the paper feeding side in the transfer section can be corrected.

In the electrophotographic apparatus according to the third aspect, the predetermined time is the time until the leading edge of the image formed on the image carrier reaches the transfer section, and the leading edge of the recording paper reaches the transfer section. By setting the time difference up to the time difference, it is possible to match the timings of the image forming side and the paper feeding side in the transfer section.

In the electrophotographic apparatus according to the fourth aspect, by delaying the start of the image forming operation for each selected sheet feeding unit for a certain period of time, the operation of the image forming unit is controlled when the hard copy is output by the optional sheet feeding. It is possible to start at the same timing as the feeding of the main body, suppress the electrostatic exposure and physical wear of the photoconductor, and further suppress the physical wear of the drive system to reduce the running cost.

In the electrophotographic apparatus according to claim 5, the fixed time is the time until the recording paper fed from the main body paper feeding unit reaches the transfer portion, and the paper is fed from the selected paper feeding unit. It is possible to match the timings of the image forming side and the sheet feeding side in the transfer section by setting the time difference until the recording paper reaches the transfer section.

In the electrophotographic apparatus according to the sixth aspect, when the optional sheet feeding unit is selected, before the sheet feeding operation is started, it is synchronized with the image on the image carrier at the same timing as the sheet feeding timing of the main body sheet feeding. By pre-feeding the recording paper to a position where it can be removed and making it stand by, the photoconductor rotation speed is set to the same minimum rotation speed as in the case of main body feeding, and electrostatic exposure and physical abrasion of the photoconductor, and further The physical wear of the drive system can be suppressed and the running cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment of the present invention.

FIG. 2 is a flowchart for explaining another embodiment of the present invention.

FIG. 3 is a flowchart for explaining a modified example of FIG.

FIG. 4 is a flowchart for explaining yet another embodiment of the present invention.

FIG. 5 is a flowchart continued from FIG. 4;

FIG. 6 is a flowchart for explaining a modified example of FIG.

FIG. 7 is a flowchart continued from FIG. 6;

FIG. 8 is a schematic configuration diagram for explaining a conventional electrophotographic apparatus.

FIG. 9 is a flowchart for explaining control of a conventional electrophotographic apparatus.

[Explanation of symbols]

 1 Photoreceptor 2 Charging Section 3 Optical Writing Section 4 Developing Roller 5 Transfer Section 6 Fixing Section 7 Paper Ejection Section 8 Cleaning Section 9 Electrification Section 10 Recording Paper 11 Paper Feeding Roller 20 Recording Paper Detection Means 211 Main Body Paper Feeding Section 221 Option 1 Supply Paper unit 222 Option 2 paper feed unit 231 Simple paper feed unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 1/00 108 H04N 1/00 108M 108Q

Claims (6)

[Claims] 1. An optional paper feed unit is provided in addition to the main body paper feed unit, and recording is performed regardless of whether the paper is fed from the main body paper feed unit or the optional paper feed unit upstream of the transfer section. A recording paper detection unit is provided at a position where the leading end position of the paper can be detected, and the recording paper is temporarily stopped when the leading end position of the recording paper is detected by the recording paper detection unit.
An electrophotographic apparatus which resumes conveyance toward the transfer section, wherein an image forming operation is started based on detection by the recording sheet detection means. 2. When the time required for the leading edge of the recording paper to reach the transfer portion is shorter than the time required for the leading edge of the image formed on the image carrier to reach the transfer portion, image formation is performed. The electrophotographic apparatus according to claim 1, wherein after the operation is started, the conveyance of the recording paper is restarted with a delay of a predetermined time. 3. The time difference between the time required for the leading edge of the image formed on the image carrier to reach the transfer section and the time required for the leading edge of the recording paper to reach the transfer section. The electrophotographic apparatus according to claim 2, which is equivalent. 4. An optional paper feed unit in addition to the main body paper feed unit, means for selecting a paper feed unit according to the size of recording paper, and an image forming operation for a certain time for each selected paper feed unit. And a means for delaying the start of the electrophotographic apparatus. 5. The fixed time is the time until the recording paper fed from the main body paper feeding unit reaches the transfer unit, and the recording paper fed from the selected paper feeding unit is transferred to the transfer unit. The electrophotographic apparatus according to claim 4, wherein the electrophotographic apparatus is equivalent to a time difference between the arrival times. 6. A recording apparatus which has an optional paper feeding unit in addition to the main body paper feeding unit, and which is upstream of the transfer unit and which is fed from either the main body paper feeding unit or the optional paper feeding unit. A recording paper detection unit is provided at a position where the leading end position of the paper can be detected, and the recording paper is temporarily stopped when the leading end position of the recording paper is detected by the recording paper detection unit.
In the electrophotographic apparatus that resumes conveyance toward the transfer unit, when the optional sheet feeding unit is selected, the image on the image carrier is imaged at the same timing as the sheet feeding timing of the main body sheet feeding before the sheet feeding operation is started. An electrophotographic apparatus having means for pre-feeding recording paper to a position where it can be synchronized with.